Disc pad assembly without backing plate

ABSTRACT

A disc brake assembly includes a brake pad support member including a wall forming an aperture. A pad is at least partially disposed in the aperture. The pad is constructed from a friction material defining a front friction face and a back face opposite the front face. A perimeter is arranged between the faces. An insert is embedded the pad between the faces and preferably extends to the perimeter adjacent to the wall with the insert receiving the lateral load during braking. Preferably, the insert extends to the back face with a terminal portion of the insert flush with the back face for receiving a brake actuation load. The insert includes a protrusion that locates the insert relative to the friction material during the disc pad forming process. The brake actuator is supported by the brake pad support member for exerting a brake actuation load on the back face of the brake pad, preferably on the insert. If desired, a load plate may be arranged between the brake and the actuator, or the disc brake assembly and pad may be designed such that a piston engages the pad where the brake actuation load may be exerted on the insert.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a disc brake assembly, and moreparticularly, the invention relates to a disc pad for a disc brakeassembly without a conventional disc pad backing plate.

[0002] Disc brake assemblies are widely used in the automotive andcommercial trucking industries. A pair of disc pads are arranged oneither side of the annular surfaces of a brake rotor. Application of abrake actuator forces friction linings of the disc pad into engagementwith the annular surfaces thereby slowing the rotation of the rotor andbraking in the vehicle. Rotation of the rotor during braking introduceslateral loads on the perimeter of disc pad. The disc pad must withstandthe brake actuation load and lateral loads on the perimeter on the brakepad during braking.

[0003] Conventional brake pads typically employ a friction material thatis riveted or molded to a steel backing plate. The friction materialwears up to the rivets at which point the disc pad must be discarded.The backing plate is a rather large piece of steel designed to take thelateral loads and brake actuation loads. The backing plate is discardedonce the friction material has worn away, which is a significant cost ofthe disc pad. Some disc brake assemblies incorporate a load platebetween the backing plate of the disc pad and the brake actuatorrendering the large backing plate some what unnecessary. The disc padopposite the disc pad that is in engagement with the load platetypically abuts a support member such as a caliper or saddle, which alsorenders the large backing plate for that disc pad rather unnecessary.Therefore, what is needed is a disc pad that eliminates the large costlybacking plate while withstanding brake actuation and lateral loads.

SUMMARY OF THE INVENTION AND ADVANTAGES

[0004] The present invention provides a disc brake assembly including abrake pad support member including a wall forming an aperture. A pad isat least partially disposed in the aperture. The pad is constructed froma friction material defining a front friction face and a back faceopposite the front face. A perimeter is arranged between the faces. Aninsert is embedded the pad between the faces and preferably extends tothe perimeter adjacent to the wall with the insert receiving the lateralload during braking. Preferably, the insert extends to the back facewith a terminal portion of the insert flush with the back face forreceiving a brake actuation load. The insert includes a protrusion thatlocates the insert relative to the friction material during the disc padforming process. The brake actuator is supported by the brake padsupport member for exerting a brake actuation load on the back face ofthe brake pad, preferably on the insert. If desired, a load plate may bearranged between the brake and the actuator, or the disc brake assemblyand pad may be designed such that a piston engages the pad where thebrake actuation load may be exerted on the insert.

[0005] Accordingly, the above invention provides a disc pad thateliminates the large costly backing plate while withstanding brakeactuation and lateral loads.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Other advantages of the present invention can be understood byreference to the following detailed description when considered inconnection with the accompanying drawings wherein:

[0007]FIG. 1 is an exploded perspective view of a prior art disc brakeassembly;

[0008]FIG. 2 is a cross-sectional view of prior art disc brake assembly;

[0009]FIG. 3 is an enlarged cross-sectional view of the presentinvention disc brake assembly with disc pad;

[0010]FIG. 4 is a rear view of the back face of the disc pad; and

[0011]FIG. 5 is a rear view of another disc pad back face.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0012] An exploded portion of a disc brake assembly 10 is shown in FIG.1 and in cross-section in FIG. 2. The assembly 10 includes a brake padsupport member that may include a caliper 12 with a saddle 14 supportedby the caliper 12 typically with pins. Brake pads 16 are supported bythe saddle 14 on either side of a rotor 18. A brake actuator 20 is shownschematically in FIG. 1, and is supported by the caliper 12. The brakeactuator 20 produces a brake actuation load on the brake pads 16typically by a load plate 36 arranged between the brake actuator 20 andone of the brake pads 16. A typical brake actuator 20 is best shown inFIG. 2. The actuator 20 shown in FIG. 2 includes a shaft 22 with a ball24 arranged between the shaft 22 and a ramp 26. Rotation of the shaft 22moves the ramp structure 26 axially forcing the pads 16 into engagementwith the rotor 18.

[0013] The saddle 14 includes a walls 28 and 29 defining an aperture 30for supporting each of the pads 16. Prior art pads typically include asteel backing plate 32 riveted or molded to friction material 34. Thesteel backing plates 32 take the brake actuation load and the lateralload produced between the backing plate 32 and the walls 28 and 29 asthe rotor 18 grabs the friction surface 34 during braking. The rotorencourages the pad 16 to spin and the side walls 26 take the lateralload. The wall 29 takes the load from the pad 16 caused by vibrationsfrom the road. The back surface of the pad 16 opposite the actuator 20and load plate 36 is typically supported by an inner surface of thecaliper 12 during braking.

[0014] The present invention eliminates the large steel backing plate 32that are discarded when the brake pads have worn. Instead the presentinvention brake pads utilize an insert 44, shown in FIG. 3, to take thebrake actuation load and lateral load. The brake pad 16 include a backface 38 that is typically in engagement with a load plate 36, a brakeactuation piston, or component or a brake pad support structure such asan inner surface of the caliper 12. A front friction face 40 is spacedfrom the back face 38 and engages the rotor 18 during braking. The brakepad 16 also includes a perimeter 42 arranged between the faces 38 and40. A portion of the perimeter 42 is adjacent to the walls 28 and 29 tolaterally locate the brake pad 16. The insert 44 is embedded in thefriction material between the faces 38 and 40, and provides thestructural integrity for the disc pad 6. The insert 44 also preferablyextends to the perimeter adjacent to the wall for receiving the lateralload during braking. Preferably, the insert 44 also extends to the backface with a terminal portion 46 of the insert flush with the back face38 for receiving the brake actuation load. In this manner, the insert 44receives the loading to which the brake pad 16 is subjected duringnormal braking.

[0015] The insert includes a protrusion 48 or locating feature thatextends inwardly away from the perimeter 42 to locate the insert 44relative to the friction material 34. The insert 44 defines at least aportion of the outer surface of the brake pad such as the perimeter 42or the back face 38. The friction material is molded about the insert tosurround the locating feature. The wearable portion W of the disc pad isdefined by the thickness of the friction material F minus the thicknessof the insert 44 I. The width of the insert T is relatively thin such asapproximately 1 millimeter. Of course, as to be understood that thedimensions of the insert may be determined by the particular loading towhich the disc pads will be subjected during brake use.

[0016] The insert may be arranged about the entire perimeter of the discpad, as shown in FIG. 4. Alternatively, multiple inserts may be used andarranged about the disc pad 16 in locations in which it is needed fortaking the brake actuation and lateral loads. For example, two inserts44 may be spaced from one another on opposing lateral sides adjacent toopposing lateral sides of the wall 28 for taking the lateral load. Itshould be understood that any number of inserts 44 may be used andlocated appropriately for the loading of a particular disc brakeassembly configuration.

[0017] The invention has been described in an illustrative manner, andit is to be understood that the terminology that has been used isintended to be in the nature of words of description rather than oflimitation. Obviously, many modifications and variations of the presentinvention are possible in light of the above teachings. It is,therefore, to be understood that within the scope of the appended claimsthe invention may be practiced otherwise than as specifically described.

What is claimed is:
 1. A brake pad for use with a disc brake assemblycomprising: a pad constructed from friction material defining a frontfriction face and a back face opposite said front face with a perimeterarranged between said faces; and an insert embedded in said pad betweensaid faces and extending to said perimeter for receiving a lateral load.2. The brake pad according to claim 1, wherein said insert extends tosaid back face with a terminal portion of said insert flush with saidback face for receiving a brake actuation load.
 3. The brake padaccording to claim 2, said insert includes a protrusion extendinginwardly away from said perimeter locating said insert relative to saidfriction material.
 4. The brake pad according to claim 1, including aplurality of inserts spaced from one another.
 5. The brake pad accordingto claim 1, wherein a distance between said faces less a width of saidinsert defines a wearable pad thickness.
 6. The brake pad according toclaim 5, wherein said insert includes an insert thickness transverse tosaid width, said insert thickness approximately 1 millimeter.
 7. Thedisc brake assembly comprising: a brake pad support member including awall forming an aperture; a pad at least partially disposed in saidaperture, said pad constructed from friction material defining a frontfriction face and a back face opposite said front face with a perimeterarranged between said faces; an insert embedded in said pad between saidfaces and extending to said perimeter adjacent to said wall with saidinsert receiving a lateral load during braking; and a brake actuatorsupported by said brake pad support member exerting a brake actuationload on said back face of said brake pad.
 8. The brake assemblyaccording to claim 7, wherein said brake pad support member includes acaliper and a saddle supported by said caliper with said aperture insaid saddle, wherein said caliper supports said brake actuator.
 9. Thebrake assembly according to claim 7, wherein a load plate is arrangedbetween said brake actuator and said back face, said insert including aterminal portion flush with said back face, said terminal portionreceiving said brake actuation load.
 10. The brake assembly according toclaim 7, wherein said aperture has opposing lateral sides with aplurality of inserts spaced from one another and adjacent to saidopposing lateral sides.
 11. A method of forming a brake pad comprisingthe steps of: a) providing an insert defining at least a portion of anouter surface of a brake pad with the insert having a locating feature;b) molding a friction material about the insert and surrounding thelocating feature; and c) defining a wearable pad thickness by a frictionmaterial thickness less an insert thickness.
 12. The method according toclaim 11, wherein the outer surface is a perimeter arranged between apad front friction face and a pad back face opposite the front face, theinsert extending to the perimeter for receiving a lateral load.
 13. Themethod according to claim 11, wherein the outer surface is a pad backface opposite a pad front friction face opposite the back face.